1. Field of the Invention
The present invention relates to an information processing device, an information processing method, a program, and a recording medium. Particularly, the present invention relates to an information processing device, an information processing method, a program, and a recording medium that are favorably used to recommend predetermined information to a user.
2. Description of the Related Art
The widespread diffusion of the Internet has enabled users to easily search for desired information. Also, purchase of items at a shop on the Internet (a so-called net shopping) has become widespread.
For example, a user searches for a shop that sells a necessary item on the Internet, determines the shop on the Internet on the basis of information provided as a search result, and purchases the item at the shop.
Under these circumstances, the user side wants a function enabling easier search for items, whereas the shop side wants a function enabling more efficient selling of items. In accordance with such a demand, for example, when a user purchases an item, the shop recommends another item related to the purchased item. Accordingly, the user can advantageously know (recognize) the related item(s) and purchase the items at the same time (purchase a plurality of items at one time by saving a trouble). Also, the selling side can efficiently sell items because a plurality of items can be sold at the same time advantageously.
As such a recommending method, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2002-334256) suggests a method using a collaborative filtering device. In recommendation using the collaborative filtering device, on the basis of personal information such as a history of items purchased by a user (user A), another user (user B) having a history similar to the history of user A is selected. Then, recommended information is selected from the history of the selected user B (for example, information common to the users A and B is selected as recommended information), and the selected information is provided to the user A.
On the other hand, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2002-215665) suggests a method using content-based filtering. According to this suggestion, a sentence in content is represented as a vector of a keyword, the keyword represented by the vector is weighted in a TF (term frequency)×IDF (invert document frequency) method or the like, and cosine measure in a vector space is used as similarity. Accordingly, similar content is searched for and a search result is recommended to the user side.